title: Bony nasolacrimal duct entrance diameter: gender difference in cadaveric study.
abstract: OBJECTIVE
  To examine gender differences in bony nasolacrimal canal entrance diameters in cadavers.
  
  
  METHODS
  Fifty-seven orbits from 29 Japanese cadavers (37 orbits from 19 men and 20 orbits from 10 women), aged 61 to 96 years at death (mean: 79.5 years; men: 77.8 years; women: 82.7 years), were fixed in 10% buffered formalin. The anteroposterior and transverse diameters of the bony nasolacrimal canal entrance were measured. The diameters were compared between genders using Student's t test.
  
  
  RESULTS
  The mean anteroposterior diameters in all subjects, men, and women, were 6.9, 6.8, and 7.2 mm, and the equivalent transverse diameters were 5.7, 6.1, and 5.0 mm, respectively. There was no significant gender difference in the anteroposterior diameter (p = 0.287), but the transverse diameter was significantly shorter in women than in men (p = 0.004).
  
  
  CONCLUSIONS
  The transverse diameter of the bony nasolacrimal canal entrance was significantly shorter in women than in men, which may be a possible factor contributing to the higher incidence of primary acquired nasolacrimal duct obstruction in women.
authors.affiliation: Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kakizaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000033:anatomy & histology; D009301:Nasolacrimal Duct / Q000033:anatomy & histology*; D012737:Sex Factors